Tissue penetrating catheters having integral imaging transducers and their methods of use

ABSTRACT

A catheter device that is useable to penetrate from a blood vessel in which the catheter device is positioned to a target location comprises a flexible catheter advanceable into the first blood vessel, a tissue penetrator lumen adapted to receive an operative tissue penetrator which is usable to penetrate from the blood vessel to the target location when properly aimed. Further said catheter including an imaging transducer fixedly mounted on or within the catheter body to provide an imaging signal from which an image of the target location can be obtained. The catheter device may include an imageable marker on the catheter to form on the image obtainable from the imaging signal a penetrator path indication that indicates the path that will be followed by the tissue penetrator when the tissue penetrator exits from the catheter. Alternatively, or addition thereto, the imaging transducer may comprise a plurality of imaging elements which are located so that the penetrator path indication can be obtained. A method of utilizing such a catheter device to bypass an arterial obstruction is also disclosed.

RELATED APPLICATION

This application claims priority to United States ProvisionalApplication No. 60/080,196 filed Mar. 31, 1998 and is acontinuation-in-part of U.S. patent application Ser. No. 08/837,294filed on Apr. 11, 1997, which itself is a continuation-in-part oftwo-earlier filed applications, namely; U.S. patent application Ser. No.08/730,327 filed Oct. 11, 1996 and 08/730,496 now U.S. Pat. No.5,830,222, both of which were filed on Oct. 11, 1996 and both of whichclaim priority to earlier-filed U.S. Provisional Patent Application Nos.06/005,164 filed Oct. 13, 1995 and 60/010,613 filed Feb. 2, 1996, theentire disclosures of all such related applications being expresslyincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to medical devices and methods,and more particularly to catheter devices and methods that are useableto form channels (e.g., penetration tracts) between vessels such asarteries and veins and vessels and other anatomical structures, infurtherance of a therapeutic purpose such as bypassing an arterialblockage, delivering therapuetic agents, or performing otherinterventional procedures.

BACKGROUND OF THE INVENTION

Atherosclerotic cardiovascular disease remains a major cause ofpremature death and morbidity, in most regions of the world. Varioustransluminal, catheter-based interventional techniques have been used,or proposed for use, to dilate or otherwise treat atheroscleroticobstructions that occur in coronary and/or peripheral arteries. Thesetherapies have traditionally focused on treating the diseaseintraluminally, or from “within” the vessel lumen.

Included among the newer interventional techniques are certainpercutaneous, transluminal techniques for bypassing obstructions incoronary or peripheral arteries through the use of the adjacent vein(s)as in situ bypass conduit(s); (e.g. using catheters to perform extraluminal procedures outside the diseased vessel lumen. These proceduresare described in U.S. Pat. No. 5,830,222 (Makower) and in published PCTApplications WO 98/16161 and WO 98/46119. As described therein, in someinstances, these procedures may be performed by a venous approachwherein a tissue penetrating catheter is inserted into a vein and thedesired passageway or puncture is initially formed by facilitating thepassage of a tissue penetrator (e.g., a flow of energy or an elongatepenetration member) from a catheter, through the wall of the vein inwhich the catheter is positioned, and into a target location such as thelumen of an adjacent vessel (e.g. the artery). Alternatively, some ofthese procedures may be performed by an arterial approach wherein thecatheter is inserted into an artery and the desired passageway orpuncture is initially formed by facilitating the passage of a tissuepenetrator (e.g., a flow of energy or elongate penetration member) fromthe catheter, through the wall of the artery in which the catheter ispositioned, and into the target location such as the lumen of anadjacent vessel (e.g. a vein). It is typically necessary for thetissue-penetrating catheter to be placed in proper rotationalorientation within the blood vessel, prior to facilitating the passageof the tissue penetrator therefrom, to ensure that the tissue penetratoris aimed or positioned to enter the target. To facilitate such aiming ofthe tissue penetrator, some of the previously described tissuepenetrating catheters have included a penetrator direction marker thatindicates the direction in which the tissue penetrator will pass fromthe catheter and an imaging catheter lumen through which a separateintravascular ultrasound imaging catheter (IVUS catheter) can beadvanced. After the separate IVUS catheter has been advanced into theimaging lumen of the tissue penetrating catheter, the IVUS is used toimage the target and the penetrator direction marker. The catheter canthen be rotated within the blood vessel until the penetrator directionmarker is aligned with the target, thereby indicating that subsequentadvancement of the tissue penetrator from the catheter will result inthe formation of the desired penetration tract between the blood vesselin which the catheter is positioned and the target.

Applicant has determined that, in cases where the tissue-penetratingcatheter is to be placed in a relatively small blood vessel such asbranches of the coronary artery, carotid arteries, or smaller vesselslocated in the peripheral vasculature (e.g. vessels in the arms orlegs), it is desirable for the tissue penetrating catheter to be ofreduced profile while still having sufficient column strength and torquetransfer properties to allow the operator to rotate and maneuver thedistal end of the catheter within the patients body by twisting, pushingand pulling the proximal end of the catheter that remains outside of thepatient's body. Thus, because the provision of a separate imagingcatheter lumen substantially increases the required diameter of thetissue penetrating catheter, it is desirable to devise new tissuepenetrating catheter designs that do not include an imaging catheterlumen while still maintaining the capability of imaging from a vantagepoint near the catheter's distal end to facilitate proper rotationalorientation of the tissue penetrating catheter to facilitate aiming ofthe tissue penetrator.

SUMMARY OF THE INVENTION

This invention facilitates accurate and reliable orientation of a tissuepenetrating catheter in a blood vessel so that an adjacently locatedblood vessel or other anatomical target can be accurately penetrated,while eliminating the need for formation of a separate imaging lumenwithin the tissue penetrating catheter. Thus, because the need for animaging lumen has been eliminated, the tissue penetrating catheters ofthis invention may be of reduced profile (e.g., 5-7 French diameter).

In accordance with the invention, there is provided a tissue penetratingcatheter device that comprises an elongated catheter having aninstrument lumen to facilitate the passage of a tissue penetrator, apenetrator direction marker, and an integral imaging transducer (e.g.,an IVUS transducer). To facilitate orientation, the imaging transduceris useable to provide an imaging signal from which an image of thetarget structure and other adjacent anatomical structures can beobtained. The imaging transducer is fixedly mounted on or within thecatheter, thereby eliminating the need for a separate imaging lumenwhich requires sufficient clearance in the lumen to allow a separateimaging transducer to be advanced and retracted in the lumen. This inturn enables the catheter to be of smaller cross sectional area. Inaddition, by fixedly mounting the imaging transducer on the catheter,its orientation relative to the catheter and certain components on thecatheter can be specifically known.

One advantageous approach to imaging is to employ an imaging transducerwhich includes a plurality of imaging elements fixedly mounted on thecatheter to provide an imaging signal from which an image of adjacentstructures can be obtained. The imaging elements are mounted on thecatheter at known circumferential locations relative to the path thatwill be followed by the tissue penetrator as the tissue penetrator exitsfrom the catheter. The image obtained from the imaging signal from theimaging transducer is useable by the operator to rotationally orient thecatheter such that, when the tissue penetrator subsequently exits thecatheter, the tissue penetrator will extend into the desired target. Inaddition, the imaging transducer is useable to image other structures toallow several diagnostic functions such as assessing calcification of avessel, distance of the target location to the vessel in which thecatheter is positioned, and the presence of other devices.

Another advantageous approach to imaging is to provide an imaging markeron the catheter to form, on the image obtainable from the imaging signalfrom the imaging transducer, a penetrator path indication. Thispenetrator path indication is indicative of the path that will befollowed by the tissue penetrator when the tissue penetrator exits fromthe catheter. The imaging transducer and the marker are useable incooperation with each other to enable the operator to rotationallyorient the catheter until the penetrator path indicator is aimed at thetarget thereby indicating that when the tissue penetrator exits from thecatheter it will extend to the target as desired. The imaging elementsfixedly mounted on the catheter at known circumferential locations canalso be used to orient the catheter without any imageable markers.

When an imageable marker is used, it preferably includes a structureformed on the catheter including at least one longitudinal memberdisposed circumferentially about a hollow interior space. When aplurality of longitudinal members is employed, said longitudinal membersare disposed at circumferentially spaced apart locations about a hollowinterior space thereby forming a cage. At least one of such longitudinalmembers is located at a circumferential position that is axially alignedwith the path or plane of the path that will be followed by the tissuepenetrator as it exits from the catheter.

The tissue penetrator may be any instrument for penetrating the targetof interest. For example, the tissue penetrator may be or include alaser beam, flow of energy, or an instrument which will itself punctureor penetrate the target of interest. One preferred form of tissuepenetrator includes a needle member formed of resilient material that isbiased to a preformed curved configuration with the needle member beinginitially disposed in a retracted position within the catheter andsubsequently advanceable from the catheter to an extended positionwherein the needle member assumes its preformed curved configuration.

The imaging transducer of the current invention is preferably anultrasound imaging transducer and more preferably a phased arraytransducer. Because the phased array transducer can be fixed in apermanent manner on or within the catheter body, said phased arraytransducer has the advantage of being useable with or with out animageable marker to obtain reliable and accurate orientation. Moreover,the nature of the imaging elements and the fact the imaging signal canbe transmitted by multiplexing numerous signals on fewer lead wirescontribute to the small profile of the catheter.

The catheter may include an elongated catheter body having a proximalend, a distal end and a peripheral wall with at least a distal region ofthe catheter body being flexible enough to navigate through the coronaryvessels. The catheter body has an penetrator lumen that terminatesdistally at an exit location on the peripheral wall and contains or isadapted to receive an instrument or other tissue penetrator forpenetrating the blood vessel in which the catheter body is received(“resident blood vessel”) to a target adjacent to the resident bloodvessel. The phased array transducer is preferably an onboard transducerwhich is mounted on or within the catheter body and is inseparable ornot removable from the catheter body. The phased array transducer iscarried by the catheter body in fixed relationship to the catheter bodyand in some instances, in a known orientation relative to the exitlocation. The phased array transducer provides an imaging signal for usein locating the target and identifying the angular orientation of theexit location. Accordingly, with the penetrator received in thepenetrator lumen the catheter body can be rotated to properly orient theexit location so that the penetrator can penetrate the resident bloodvessel into which the catheter body is receivable and into the target.The catheter body is of sufficiently small profile so that it can bereceived within a coronary artery, branch or peripheral vessel ifdesired.

The catheter may be considered as including an imageable marker whichmay include a plurality of circumferentially spaced imageable memberscarried by the catheter body in a known circumferential orientationrelative to the exit location. The imageable markers can be sensed bythe phased array transducer and used to locate the target and inidentifying the angular orientation of the exit location.

The phased array transducer may comprise a plurality of imaging elementsarranged on the catheter body with at least one of the elements being ata known circumferential location relative to the exit location so thatsuch at least one element is useable to identify the angular orientationof the exit location. Alternatively or in addition thereto, the at leastone element may form an image region that defines an acceptable zone ofpenetration for the tissue penetrator.

In a preferred construction, the catheter body includes a major sectionwhich includes a proximal end and the exit location and a distal tipsection extending from the major section to the distal end. The distalportion of the distal tip section has a smaller cross sectional areathan the adjacent region of the major section. An active imagingapparatus is carried by the catheter body and includes imaging elementsfixedly mounted on the distal tip section and a lead or leads extendingproximally from the imaging elements along the catheter body.Accordingly, the reduced diameter portions of the catheter body are usedto mount the imaging elements, to thereby minimize the profile of thecatheter at this region of the catheter. Although various constructionsare possible, in one preferred form of the invention, the major sectionterminates distally in a distal opening and a proximal portion of thedistal tip section is received in the distal opening and a distalportion of the distal tip section extends distally of the distalopening.

The method of this invention includes inserting and transluminallyadvancing the catheter of this invention into a first blood vessel,actuating the imaging transducer and moving the catheter within thefirst blood vessel until the penetrator path indication is aimed at thetarget, and thereafter facilitating the exit of the tissue penetratorfrom the catheter through the wall of the first blood vessels and intothe target. Thereafter various procedures may be performed such as thedelivery of therapeutic agents or diagnostic devices.

In procedures where it may be advantageous to perform subsequentprocedures over a guidewire, such as the formation of passagewaysbetween a first blood vessel and a target, the method may also includeadvancing a first crossing guidewire through the lumen of the tissuepenetrator and into the target, such as the lumen of the second bloodvessel or other target and retracting the tissue penetrator into thecatheter leaving the first crossing guidewire in place.

In some procedures, such as those novel procedures more fully describedin U.S. Pat. No. 5,830,222 and in U.S. patent applications Ser. Nos.08/730,496, 09/048,147 and 09/048,147, and other means ofrevascularizing oxygen starved tissues or delivering therapueticsubstances to vessels, tissue and other organs, it may be advantageousto obtain a second point of access to the same vessel into which thecatheter was initially introduced at some point distal of the firstcrossing. However, this access may be limited due to the presence ofcalcium or other vessel disease blocking the lumen of the vessel. Toobtain catheter access to a second point, distal of a diseased sectionin the same blood vessel, the first crossing guidewire is removed fromthe lumen of the tissue penetrator and reintroduced into the mainguidewire lumen of the catheter and the catheter may be readvanced overthe first crossing guidewire to a position wherein the catheter extendsthrough the lumen of the first blood vessel, and through the openingscreated in the walls of the first and a second blood vessel. Thereafter,the catheter can be advanced distally in the lumen of the second bloodvessel. To gain access back to the first blood vessel at a differentlocation (e.g. past the disease or obstruction), the imaging transduceris actuated and the catheter is moved within the second blood vessel asrequired to cause the penetrator path indication to be aligned with thelumen of the first blood vessel. The tissue penetrator is advanced fromthe catheter through the wall of the second blood vessel and through thewall and into the lumen of the first blood vessel. To obtain guidewireaccess to the first blood vessel, a second crossing guidewire isadvanced through the lumen of the tissue penetrator and into the lumenof the first blood vessel. The tissue penetrator is retracted into thecatheter leaving the second crossing guidewire in place such that itextends from the lumen of the first blood vessel into the lumen of thesecond blood vessel and back into the lumen of the first blood vessel.

As part of the invention envisioned herein, a radial expandableconnector can be used to provide a blood flow passageway between theblood vessels. For example, a connector delivery catheter can beadvanced over the second crossing guidewire and the connector implantedsuch that the connector extends from the lumen of the first blood vesselthrough the openings created in the walls of the first and second bloodvessels through the lumen of the second blood vessel through theopenings created in the walls of the first and second blood vessels andback into the lumen of the first blood vessel.

The invention together with additional features and advantages thereofmay best be understood by reference to the following description takenin connection with the accompanying illustrated drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is schematic illustration showing the catheter of this inventionin use on a human patient.

FIG. 2 is an elevational view of one form of catheter constructed inaccordance with the teachings of this invention.

FIG. 3a is an enlarged fragmentary elevational view partially in sectionshowing a distal portion of the catheter.

FIG. 3a′ is an enlarged, cut-away view of the wire braid formed withinthe distal section of the catheter body.

FIG. 3a″ is a diagram of a catheter braid illustrating the braid angleand pick count of the braid.

FIG. 3b is an enlarged elevational view showing the distal tip sectionof the catheter.

FIGS. 3c, 3 d and 3 e are cross sectional views taken generally alonglines 3 c—3 c, 3 d—3 d, and 3 e—3 e of FIG. 3 respectively.

FIG. 3f is a perspective view of the marker structure of the catheterembodiment shown in FIGS. 3a-3 b.

FIG. 3g is a cross sectional view through FIG. 3g—3 g of FIG. 3a.

FIG. 4 is an elevational view similar to FIG. 3a illustrating a secondembodiment of the catheter.

FIGS. 4a and 4 a′ are schematic diagrams of a annular phased arraytransducers that may ne mounted within catheters of the presentinvention.

FIG. 4b is a schematic diagram of an alternative single elementtransducer that is rotatable within or in conjunction with the catheter.

FIGS. 5a and 5 b are elevational views of the screen of the imagingapparatus showing standard quadrant-indicating hash marks on the screen,and illustrating the manner in which the fixed-transducer catheter ofFIG. 4 can be rotationally oriented within the blood vessel to cause apenetrator-path-indicating element (and hence the penetrator) to becomeaimed at a target location to which the penetrator is intended totravel.

FIGS. 5c and 5 d are elevational views of the screen of an imagingapparatus whereon a line has been marked to denote the location of theparticular penetrator-path-indicating element of the fixed-transducercatheter of FIG. 4, and illustrating the manner in which the line can beused to facilitate rotational orientation of the catheter within theresident blood vessel such that the penetrator-path-indicatingtransducer element (and hence the penetrator) are aimed at the targetlocation.

FIGS. 5e and 5 f are elevational views of the screen of an imagingapparatus displaying an image from a fixed-transducer catheter as inFIG. 4 wherein the penetrator-path-indicating element(s) of the imagingtransducer is/are electronically modified to produce an image that is i)visually distinct from the images produced by the other elements of thetransducer array, or ii) modified to produce multiple lines that definea path region, and illustrating the manner in which the visuallydistinct image of the penetrator-path-indicating transducer can be usedto facilitate rotational orientation of the catheter within the residentblood vessel such that the penetrator-path-indicating transducer element(and hence the penetrator) are aimed at the target location orconversely, the path region incorporates the target location within itsscope.

FIGS. 6a and 6 b are views similar to FIGS. 5a and 5 b respectivelyillustrating how the catheter embodiment of FIG. 3a can be rotationallyoriented within the blood vessel to cause the image created by thepenetrator-path-indicating member of the marker structure (i.e., theparticular strut member of the marker structure that is aligned with thepath that will be followed by the tissue penetrator when the penetratoris advanced from the catheter body) to be aimed at the target locationto which the penetrator is intended to travel.

FIGS. 7a-8 d illustrate the triangle of Brock-Moscheau (a name given tothe formation bounded by the relationship between the arterial andvenous system on the heart) and show by way of example as preferredmethod that can be carried out in accordance with the teachings of thisinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Set forth herebelow are detailed descriptions of certain embodiments andexamples of the catheter devices and methods of the present invention.

First Embodiment: Catheter With Phased Array (or Rotatable) ImagingTransducer and Marker Structure For Indicating Penetrator Path

FIG. 2 shows a catheter 11 constructed in accordance with the teachingsof this invention, while FIG. 1 shows the catheter 11 in use on a humanpatient. In the embodiment illustrated, the catheter 11 includes anelongated catheter body 13 having a proximal end 15, a distal end 17, ahandle 19 and a hub 21 coupled to the proximal end of the catheter body15 and to the handle. The handle 19 may also serve as a controller foruse in advancing and retracting the penetrating instrument, such as atissue penetrator 85 described more fully below.

The Catheter Body

The catheter body 13 includes a relatively rigid proximal section 23shown in FIGS. 2 and 3a which may be constructed, for example, of ametal hypo tube and an elongated flexible distal section or region 25suitably joined to the proximal section. A hand piece 19 is attached tothe proximal end of the proximal section 23, as shown. In the preferredembodiment the hand piece 19 and proximal section 23 are approximately100 cm in length. The flexible distal section 25 may incorporate areinforcement member such as a wire braid 400 as shown in FIGS. 3a and 3a′ and, in the preferred embodiment is approximately 30 cm in length.The braid 400 terminates approximately 3 cm from the distal end 17.

It has been determined that material expansion and changes in thephysical properties of certain materials may occur after the catheter 11is inserted into the patient's body and warmed from room temperature tobody temperature. This material expansion and changes in the physicalproperties of certain materials can result in variation in thetolerances and sizing of the catheter 11 (e.g. elongation or shrinking)and can thus give rise to an unwanted modification of the position ofthe tissue penetrating member 85. This could, in at least some cases,interfere with the precise aiming and advancement of the tissuepenetrating member as desired. FIG. 3a″ illustrates the braid angle Aand pick count PC of the catheter braid 400. The “pick count” PC of thebraid is, as is well known in the art, a function of the braid angle A(i.e., the greater the braid angle the more picks per inch). Also, thetorque transmission and stiffness of the braided distal section 25 is afunction of the braid angle (i.e., a braid angle of 90 degrees providesmaximum torque transfer and a braid angle of 0 degrees provides minimumtorque transfer). Typically, cardiovascular catheters used in proceduressuch as those described herein utilizing a venous approach have braidangles A that result in a pick count of 50-70 picks per inch. However,applicant has determined that by decreasing the braid angle A of thebraid 400 within the distal section 25 of the catheter 11 to result in alower pick count, it is possible to minimize or eliminate the unwantedlongitudinal expansion of the catheter 11 and/or its components, whileretaining sufficient torque transmission and acceptable stiffness toaccomplish the procedures for which the catheter 11 is intended(examples of such procedures are illustrated in FIGS. 7a-8 d herebelow).This variation in braid angle or picks per inch may vary depending onthe material of construction of the catheter and/or the braid fiber, andthe diameter of the catheter body.

In instances where the catheter 11 is intended for use in a coronaryartery, at least the distal section 25 of the catheter 11 is sized to bereceived within a coronary artery, and therefore can be received withineither a coronary artery or a coronary vein or other lumens of equaldiameter. The catheter body section 13 has a penetrator lumen 27 thatterminates distally at an exit location or exit port 29 (FIG. 3a) on aperipheral wall 31 of the catheter body. The penetrator lumen 27 extendsproximally from the exit port 29 to the proximal end 15 of the catheterbody 13 and communicates with the interior of the handle 19 through thehub 21. The penetrator lumen 27 contains or is adapted to receive aninstrument, such as the tissue penetrator 85 shown in FIG. 3a, forpenetrating out of the blood vessel in which the catheter 11 resides(i.e., the “resident vessel”) and to a target location. The exit port 29is preferably located a short distance proximally of the distal end 17.A radiopaque marker 33 is mounted on the lumen 27 adjacent the exit port29.

The catheter body 13 also has a guidewire lumen 35 (FIG. 3a) whichextends to the distal end 17 of the catheter body 15. In thisembodiment, the guidewire lumen 35 extends proximally to an inlet port37 at the peripheral wall 31 closely adjacent the proximal section 23.The catheter body also has a lead lumen 39 (FIG. 3c) for a purposedescribed below.

A major section 51 of the catheter body 13 terminates distally in adistal opening 53, and the catheter body includes a distal tip section55 of soft, flexible, biocompatable material (FIGS. 3a and 3 b). Aproximal portion 56 of the distal tip section 55 is received in thedistal opening 53 and a distal portion of the distal tip section extendsdistally to the distal end 17. The distal portion of the distal tipsection 55, i.e. the portion of the distal tip section 55 which extendsbeyond the distal end of the major section 51 is of smaller crosssectional area than the adjacent region of the major section to therebydefine an annular shoulder 57 on the catheter body 13. The exit port 29is spaced slightly proximally of the shoulder 57.

Phased Array Transducer

An imaging transducer 81 is fixedly mounted on the catheter 11, and inthe embodiment illustrated in FIG. 3a, the imaging transducer is mountedon the distal tip section 55 just distally of the shoulder 57. In thisembodiment, the imaging transducer 81 is a phased array transducer ofthe type shown schematically in FIG. 4a and is operative to image 360°about the catheter 11. This imaging transducer 81 comprises an annulararray of individual crystals or elements 121 is coupled to a multiplexcircuit 83 which is within the major section 51 of the catheter body 13adjacent the shoulder 57, and the multiplex circuit 83 is in turncoupled to leads 85 which extend through the lead lumen 39 and a port 87(FIG. 2) of the hub 21 to an imaging console 89. When activated, theimaging transducer emits ultrasound signals and receives back echos orreflections which are representative of the nature of the surroundingenvironment. The imaging transducer provides an imaging signal fromwhich an image of the surrounding structure can be created by signalprocessing apparatus located in the imaging console 89 and viewed on astandard display screen located near the operating table on which thepatient is positioned. In a preferred practice of this invention, thephased array transducer and the accompanying circuitry and the imagingconsole 89 may be obtained from Endosonics of Rancho Cordova, Calif. orIntravascular Research Limited (United Kingdom).

Alternative Rotatable Transducer

In an alternate embodiment of this invention, a rotatable imagingtransducer 81 r of the type illustrated schematically in FIG. 4b may beused. This alternative transducer 81 r comprises one (or more than one)imaging element 121 r that is mounted on a rotating shaft 82 thatextends through a portion of the catheter body (e.g., and out of port39) such that it can be rotated relative to the catheter body.Alternatively, it will be appreciated that this transducer 81 r may befixedly mounted within or upon the catheter body and the entire catheterbody may be rotated in order to effect rotational movement of thetransducer element 121 r.

Marker Structure

In this first embodiment (FIGS. 3a-3 e), an imageable marker structure101 is fixedly mounted on the catheter body 13 in a knowncircumferential orientation relative to the exit port 29. In theembodiment of FIG. 3a, the marker structure 101 is in the form cage(FIG. 3f) and the transducer 81 is within the cage. This markerstructure 101 comprises a plurality of longitudinal members 103 and 103pp disposed at circumferentially spaced apart locations about a hollowinterior space 105. The hollow space 105 receives the distal tip section55 and the transducer 81, and the transducer 81 is an onboard transducerin that it is inseparable from and not removable from the catheter body13. In this embodiment the transducer 81 is attached to or wrappedaround the catheter body 13 and permanently retained by a suitablepotting composition or adhesive. As shown in FIG. 3g, one of thelongitudinal members 103 pp is designated as the penetrator pathindicating member and is positioned at a circumferential position thatis axially aligned with the exit port 29 or otherwise positioned to beindicative of the path that will be followed by the tissue penetrator 85as it is advanced from the catheter body 13 through the exit port 29.Thus, the imageable marker structure 101 forms on the image obtainablefrom the imaging signal from the imaging transducer a penetrator pathindication that indicates the path that will be followed by the tissuepenetrator when the tissue penetrator 85 exits from the catheter.

With the construction described above, the imaging transducer 81 and themarker 101 are both mounted on the distal tip section 55 which has asmaller cross sectional area than does the adjacent region of the majorsection 51 of the catheter body 13. Accordingly, the cross sectionalarea of the catheter body 13 at the region containing the imagingtransducer 81 and the marker 101 can still be relatively small. Also,the exit location 29 is closely adjacent to the imaging transducer 81and may be, for example, about 3 mm from the imaging transducer. Thisminimizes the likelihood of any significant torsional displacement ofthe exit location 29 relative to the marker 101 and imaging transducer89. It may also be appreciated that the imaging transducer may bemounted such that the exit port is located directly at the point atwhich the transducer is affixed to the catheter, eliminating anydisplacement.

FIGS. 6a and 6 b show an image of what the operator sees on the displayscreen of the imaging console 89 when the catheter 11 is advanced intothe resident blood vessel. Specifically, FIG. 6a shows an image of thecatheter 11, an image 143 of the resident blood vessel into which thecatheter 11 has been inserted (i.e., the blood vessel in which thecatheter 11 resides) and an image of a target blood vessel 145 adjacentto the blood vessel 143. In this particular illustration, the bloodvessels represented by images 143 and 145 are a coronary artery andcoronary vein, respectively. In FIG. 6a, the image created by thepenetrator-path-indicating member 103 pp of the marker structure 101, asrepresented by line or artifact 147, does not extend into the lumen ofthe target blood vessel 145. Thus, if the tissue penetrator 85 were tobe advanced from the catheter 11 while the catheter 11 is in therotational orientation shown in FIG. 6a, the tissue penetrator would notadvance into the lumen of the target blood vessel 145, as desired.However, by rotating the catheter 11 within the resident blood vessel143, the operator may cause the image created by thepenetrator-path-indicating member 103 pp of the marker structure 101, asrepresented by line or artifact 147, to extend into the lumen of thetarget blood vessel 145 as illustrated in FIG. 6b. Thus, if the tissuepenetrator 85 were to be advanced form the catheter 11 while thecatheter 11 is in the rotational orientation shown in FIG. 6b, thetissue penetrator 85 would advance into the lumen of the target bloodvessel 145, as desired.

B. Second Embodiment: Catheter with Fixedly Mounted Imaging TransducerUseable Without Marker Structure

FIG. 4 shows a second embodiment of the catheter 11 a which is identicalto the catheter 11 in all respects not shown or specified as beingdifferent herebelow. Portions of the catheter 11 a corresponding toportions of the catheter 11 are designated by corresponding referencenumerals followed by the letter a.

The primary difference between the catheters 11 and 11 a is that thecatheter 11 a has no imageable marker structure 101. Instead, itsimaging transducer 81 a is mounted in a fixed position such that oneparticular element 121 pp (or a group of particular elements) is/aredesignated as the penetrator path but rather is mounted in a fixedorientation within or upon the catheter such that a selected one (orselected ones) of the individual imaging elements 121 (e.g., crystals)of the phased array is positioned in known spacial relation to the pathor plane of the path that will be followed by the tissue penetrator asexits from the catheter. This selected one (or ones) of the imagingelements 121 shall be referred to herein as the“penetrator-path-indicating element 121 pp.” The imaging elements 121,which may be adhered to the catheter body 13 a, are mounted on thecatheter 11 at known circumferential locations relative to the path thatwill be followed by a tissue penetrator as the tissue penetratoradvances from the catheter 11 through the exit port 29 a. The imageobtained from the imaging signal from the imaging transducer 81 a isthereby useable by the operator to rotationally orient the catheter 11such that when the tissue penetrator subsequently exits from thecatheter, the tissue penetrator will extend into the target as desired.Thus, because the imaging elements 121 a are mounted on the catheterbody 13 in fixed relationship to the catheter body and in a knowncircumferential orientation relative to the exit location 29 a, theimaging transducer 81 a can be used to provide an imaging signal for usein locating an adjacent blood vessel or other structure and identifyingthe angular orientation of the exit location. If desired, the imagingelements of the imaging transducer 81 of the catheter 11 can be orientedin the same fashion as described above for the catheter 11 a. In thisevent, the only difference between the catheters 11 and 11 a would bethat the catheter 11 has an imaging marker 101 and the catheter 11 adoes not.

FIG. 5a shows an image 151 of the catheter 11 a (FIG. 4) in the residentblood vessel 143 in which that catheter is positioned, as well as animage of the target location 145, shown here as another blood vessel.Standard serial hash marks 300 a, 300 b, 300 c and 300 d are formed onthe imaging screen as shown, generally dividing the screen into fourquadrants. In this instance, the transducer 81 b is fixedly mountedwithin the catheter 11 a such that its penetrator path indicatingtransducer element 121 pp is in the 12 o'clock position and aligned withthe top array of hash marks 300 a on the imaging screen. Thus, the toparray of hash marks 300 a serve as a visual indicator of the path thatwill be followed by the tissue penetrator 85 as it is advanced from thecatheter 11 a. In the showing of FIG. 5a, one can see that the top hashmarks 300 a do not enter the target location 145 and thus,it can beconcluded from this image that the tissue penetrator 85 is not properlyaimed at the target location. However, by rotating the catheter 11 a inthe resident blood vessel 143, to the position shown in FIG. 5b, the toparray of hash marks 300 a is caused to pass directly through the targetlocation 145, thus indicating to the operator that the tissue penetrator85 can now be advanced from the exit port 29 a to properly penetratefrom the resident vessel 143 into the target location 145, as desired.

FIGS. 5c and 5 d show an image 151 a of the catheter 11 a (FIG. 4) inthe resident blood vessel 143 in which that catheter is positioned, aswell as an image of the target location 145, shown here as another bloodvessel. A vertical line 146 has been created on the screen 146 inalignment with the position of a penetrator path indicating transducerelement 121 pp. of the phased array transducer 81 b. Thus, the line 146serves as a visual indicator of the path that will be followed by thetissue penetrator 85 as it is advanced from the catheter 11 a. It willbe appreciated by those of skill in the art that this line 146 may becreated on the imaging screen 89 electronically (e.g., as an illuminatedor colored line on the image) or it may be physically marked on thescreen 89 (e.g., by felt tipped marker or other suitable markingmaterial or apparatus such as a template). In the showing of FIG. 5c,one can see that the line 146 does not enter the target location 145and, thus, it can be concluded form this image that the tissuepenetrator 85 is not properly aimed at the target location 145. However,by rotating the catheter 11 a in the resident blood vessel 143, to theposition shown in FIG. 5d, the line 146 is caused to pass directlythrough the target location 145, thus indicating to the operator thatthe tissue penetrator 85 can now be advanced from the exit port 29 a toproperly penetrate from the resident vessel 143 into the target location145, as desired.

FIGS. 5e and 5 f show an image 151 b of the catheter 11 a (FIG. 4) inthe resident blood vessel 143 in which that catheter is positioned, aswell as an image of the target location 145, shown here as another bloodvessel. The penetrator path indicating element 121 pp of the phasedarray transducer 81 b has, in this case, been modified to provide animage that is enhanced or otherwise visually discernible from the imagesproduced by the other transducer elements 121 b of the array. In thismanner, a penetrator path region 148 is visible on the screen 89 in theregion that is imaged by the penetrator path indicating element 121 pp.Thus, the penetrator path region 148 serves as a visual indicator of thepath that will be followed by the tissue penetrator 85 as it is advancedfrom the catheter 11 a. It will be appreciated by those of skill in theart that this penetrator path region 148 may be created by causing thepenetrator path transducer element 121 pp to receive more power than theother transducer elements 121 b or by otherwise modifying or processingthe signal received from that penetrator path indicating transducerelement 121 pp. In the showing of FIG. 5e, one can see that the target145 is not encompassed by the penetrator path region 148 and, thus, itcan be concluded from this image that the tissue penetrator 85 is notwithin acceptable range of the target location 145. However, by rotatingthe catheter 11 a in the resident blood vessel 143, to the positionshown in FIG. 5f, the target 145 is brought within an appropriate rangeof the penetrator path region 148, thus indicating to the operator thatthe tissue penetrator 85 can now be advanced from the exit port 29 a toproperly penetrate from the resident vessel 143 into the target location145, as desired. Additionally, it is to be understood that thepenetrator path indicating transducer element 121 pp or the output onthe imaging console may be additionally modified to allow imaging orproject images of only that region within a predetermined distance (e,g,up to 3 mm) of the resident vessel 143 thereby signalling to theoperator the possible target locations that are out of the intendedrange of the tissue penetrator 85 or subsequent systems or devices thatmay be employed to complete the intended procedure.

As an alternative to creating a penetrator path region by increasing thepower transmitted to the penetrator path element transducer(s), it willbe appreciated that this region 148 may be created on the imaging screen89 electronically (e.g., as an illuminated or colored sector on theimage) or it may be physically marked on the screen 89 (e.g., by felttipped marker or other suitable marking material or apparatus such as atemplate). In addition, the penetrator path region may be defined by theenhancement (e.g. electronic illumination, marker or template) of twolines such as that depicted by line 146, modified to define boundries tothe region 148 within which is defined an acceptable range ofpenetration zone.

It will be appreciated that the electronically enhanced penetrator pathindicating transducer 121 pp may be used in conjunction with the hashmarks 300 a, 300 b, 300 c, and 300 d shown in FIGS. 5a-5 b and/or theline 146 shown in FIGS. 5c and 5 d, thereby enabling the operator toutilize multiple indicia to determine the appropriateness of the sizeand distance range of the target location 145 before advancing thetissue penetrator 85. In this way, the operator is provided with a rangeof acceptable accuracy depending on the desired result and taking intoaccount what procedures may be performed subsequently (i.e. placement ofa connection device or other catheter devices).

C. Examples of Methods and Procedures

The catheters 11 and 11 a may be used in the performance of variousrevascularization procedures including, as described in detailherebelow, a Percutaneous In Situ CoronaryArtery Bypass (PICAB)procedure as well as a Percutaneous In Situ CoronaryVenousArterialization (PICVA) procedure. It will be appreciated that, inaddition to the particular PICAB and PICVA examples described in detailherebelow, the catheter system of the present invention may also beuseable to perform various other procedures such as directed drugdelivery procedures of the type described in co-pending U.S. patentapplication Ser. No. 09/048,147 and other revascularization procedures.

i. A Preferred Method for Performing the PICVA Procedure

The PICVA procedure is useable to effectively provide arterial perfusionof an ischemic region of myocardium, even in cases where a coronaryartery is so extensively obstructed that no patent distal portion of theartery remains available to carry bypassed arterial; flow.

FIG. 7a is a diagram of a portion of the coronary vasculature known asknown as the Triangle of Brouck-Moscheau. The Triangle of Brock-Moscheauis defined by the left anterior descending coronary artery LAD, thecircumflex coronary artery CX, the anterior inter ventricular vein AIV.The arteries CX and LAD are both joined to and receive blood from theleft main artery. The great coronary vein GCV forms a downwardly openingU-shaped configuration with the legs of the U being adjacent to arteriesCX and LAD. Obstructions resulting from a build up of plaque may befound in either or both of the arteries CX and LAD. For example and forpurposes of illustrating a preferred embodiment of the method of thisinvention, FIG. 7a shows an obstruction 171 in the left anteriordescending artery LAD.

In the first step of the procedure, shown in FIG. 7b, a coronary guidecatheter 173 is advanced into the left coronary ostium and a guidewire175 such as a 0.014 inch guidewire is advanced through the guidecatheter 173 into the lumen 176 of the left anterior descending artery(LAD) to a location just proximal of the obstruction 171 as shown inFIG. 7b.

Next, as shown in FIG. 7c, the tissue penetrating catheter 11 ispercutaneously inserted and transluminally advanced through the guidecatheter 173 and over the guidewire 175 into the left anteriordescending artery LAD to a location just proximal of the obstruction 171(FIG. 7c). The axial position of the guidewire 175 and of the catheter11 within the artery LAD is known by conventional techniques which mayinclude, for example, fluoroscopy and the radiopaque marker 33. Althoughthis procedure is described with reference to the catheter 11, it shouldbe understood that an identical procedure would be followed for thecatheter 11 a. As shown in FIG. 7d, with the catheter 11 in positionwithin the LAD, the leads 85 are coupled to the imaging console 89 andthe imaging transducer 81 is actuated to obtain images as shown, by wayof example, in FIG. 6a. The catheter 11 is moved, and more specificallyrotated within the artery LAD until the exit port 29 and hence apenetrator path indication or path region 148 is aimed at the lumen ofthe vein AIV. At this point, the tissue penetrator 85 is advancedthrough the exit opening 29 from the catheter 11 through the walls ofthe artery LAD and the vein AIV and into the lumen 177 of the vein AIVupstream of the obstruction 171 as shown in FIG. 7d.

As shown in FIG. 7e, with the catheter 11 and the tissue penetrator 85in the position shown in FIG. 7d, a first crossing guidewire 179 isadvanced through the lumen 85L of the tissue penetrator 85 and into thelumen 177 of the vein AIV. The tissue penetrator 85 is then retractedinto the catheter 11 leaving the crossing guidewire 179 in place suchthat it extends from the lumen 176 of the artery LAD into the lumen 177of the vein AIV.

As shown in FIG. 7f, the catheter 11 is then removed by retracting itback over the guidewire 175 and out through the guide catheter 173leaving the guidewires 175 and 179 in place.

Thereafter, as shown in FIG. 7g, if it is necessary to enlarge or modifythe penetration tract. created by the penetrator 85, a tractmodification or enlargement apparatus 190 may be advanced over the firstcrossing guidewire 179 to enlarge or otherwise modify the penetrationtract. This tract modifying apparatus 190 may comprise a ballooncatheter or radiofrequency tissue severing device as described in U.S.patent application Ser. No. 09/056,589, the entirety of which isexpressly incorporated herein by reference.

As shown in FIG. 7h, after any necessary enlargement or modification ofthe penetration tract has been complete, the tract modifying apparatus190 and first crossing guidewire 179 are removed, leaving open thepassageway PW between the artery LAD and vein GCV/AIV. Also, a catheter191 is introduced into the coronary venous sinus CS and a guidewire 198is advanced through the catheter 191 and into the vein GCV.

As shown in FIG. 7i, the catheter 191 is then removed and a coronarysinus guide catheter 196 is introduced over the guidewire 198 into thecoronary venous sinus. A subselective sheath 192 and introducer 194 arethen advanced through the coronary sinus guide catheter 191, over theguidewire 179 and into the vein GCV proximal to the passageway PW. Thiscoronary sinus guide catheter 196, subselective sheath 192 andintroducer 194 may be of the type described in detail in concurrentlyfiled U.S. patent application Ser. No. 09/282,276 entitled CATHETERS,SYSTEMS AND METHODS FOR PERCUTANEOUS IN SITU ARTERIO-VENOUS BYPASS, theentirety of which is expressly incorporated herein by reference.

Thereafter, as shown in FIG. 7j, the introducer 194 is removed leavingthe subselective sheath 192 and guidewire 194 in place.

Thereafter, as shown in FIG. 7k, an embolic blocker 200 is advancedthrough the subselective sheath 192 and implanted in the vein GCVproximal to the passageway. This completes the PICVA procedure, allowingarterial blood to flow from the artery LAD, through the passageway PWand into the vein GCV/AIV where it flows in the direction oppositenormal venous return so as to retro-perfuse the ischemic myocardiumthrough the coronary vein(s).

i. A preferred Method for Performing the PICAB Procedure

FIGS. 8a-8 d show, in step-by-step fashion, an example of the manner inwhich a two channel PICAB procedure may be performed, or in thealternative, how the above-described PICVA procedure (FIGS. 7a-7 k) maybe converted into a two-channel PICAB procedure. This PICAB procedurewill typically be used in cases where the obstruction 171 a does notextend into the distal LAD and thus, a patent distal LAD is available tocarry blood flow to the ischemic myocarduim.

As shown in FIG. 8a, if the two channel PICAB technique is to beemployed then in lieu of the placement of the embolic blocker 200 beingplaced (starting from the step referenced in FIG. 7g) the guidewire 175is withdrawn and the catheter 11 is advanced over the crossing guidewire179 to the position shown in FIG. 8a. To accomplish this, the tissuepenetrator is retracted over the crossing guidewire 189 to remove thefirst crossing guidewire from the tissue penetrator 85 and then thecrossing guidewire 179 is introduced into the main guidewire lumen 35 ofthe catheter 11. Consequently, the catheter 11 can be advanced overthecrossing guidewire 179 to the position of FIG. 8a wherein the catheterextends through the lumen 176 of the artery LAD, through the openingscreated in the walls of the artery LAD and the vein AIV and into thelumen 177 of the vein AIV. The longitudinal or axial position of thecatheter 11 in the vein AIV relative to the obstruction 171 is knownusing conventional techniques. With the catheter 11 in the positionshown in FIG. 8a, the imaging transducer 81 is again actuated and thecatheter 11 is rotated within the vein AIV as required and as explainedabove in connection with FIGS. 6a and 6 b to cause the penetrator pathindication to be aimed at the lumen of the artery LAD at a locationdownstream of the obstruction 171. With the penetrator path indicationand the exit port 29 properly aimed at the artery 171, the tissuepenetrator 85 is advanced from the catheter 11 through the walls of thevein AIV and the artery LAD and into the lumen of the artery LAD asshown in FIG. 8a. Also, as shown, a second crossing guidewire 181 isadvanced through the lumen 85L of the tissue penetrator 85 and into thelumen of the artery LAD.

As shown in FIG. 8b, the tissue penetrator 85 is then retracted into thecatheter 11 leaving the second crossing guidewire 181 in the artery LAD.The catheter 11 and the first crossing guidewire 179 are then removedleaving the second crossing guidewire 181 in place such that it extendsfrom the artery LAD into the lumen 177 of the vein AIV and back into theartery LAD as shown in FIG. 8b.

To create a blood flow channel around the obstruction 171, an expandableconnector 191 may be employed. As shown in FIGS. 8c and 8 d, theconnector 191 is implanted such that the connector extends from theartery LAD through the openings created in the walls of the artery LADand the vein AIV, through the lumen 177 of the vein AIV, through theopenings created in the walls of the vein and artery LAD distally of theobstruction 171 and back into the artery LAD. The expandable connectormay be implanted, for example, by utilizing a connector deliverycatheter (not shown) and advancing such connector delivery catheter overthe second crossing guidewire 181. After implantation of the connector191, the second crossing guidewire is withdrawn and so is the guidecatheter 173. It will be appreciated that instead of deploying oneexpandable connector, it may be preferred to employ two shorterconnectors (not shown) at each of the first and second crossing sites.In this approach, a proximal and distal embolic blocker may be requiredto be placed in the vein proximal to the first crossing site (in theGCV) and distal to the second crossing site (in the AIV) to complete thebypass circuit.

Although exemplary embodiments of the invention have been shown anddescribed, many changes, modifications and substitutions may be made bythose having ordinary skill in the art without necessarily departingfrom the spirit and scope of this invention. For example, where thispatent application has listed the steps of a method or procedure in aspecific order, it may be possible (or even expedient in certaincircumstances) to change the order in which some steps are performed,and it is intended that the particular steps of the method or procedureclaims set forth herebelow not be construed as being order-specificunless such order specificity is expressly stated in the claim. Anotherexample is that, although the specific procedures described in detail inthis application may involve penetrating through an “acceptablepenetration zone,” such acceptable penetration zone need not be occupiedby tissue but rather such acceptable penetration zone may fully orpartially comprise an open space such as a body cavity or void.Accordingly, it is intended that all such additions, deletions,modifications and variations be included within the scope of thefollowing claims.

What is claimed is:
 1. A catheter device that is useable to penetratefrom a position within the lumen of a first blood vessel within apatient's body in which the catheter device is positioned, through thewall of that first blood vessel and to a target location located withinthe patient's body outside of that first blood vessel, said catheterdevice comprising: a catheter having a proximal end and a distal end,said catheter being advanceable into said first blood vessel; a tissuepenetrator that is advanceable from the catheter, said tissue penetratorbeing operative to penetrate from the lumen of the first blood vesselthrough the wall of that first blood vessel and to the target location;an imaging transducer located on or in the catheter for providing animaging signal from which an image of at least the target location canbe obtained; and, a marker that indicates the direction in which thetissue penetrator will advance from the catheter; said imagingtransducer and said marker being useable in cooperation with each otherto enable the operator to rotationally orient the catheter, prior toadvancement of the tissue penetrator, so that the marker indicates thatwhen the tissue penetrator is subsequently advanced from the catheter itwill extend to the target location, as desired.
 2. The catheter deviceof claim 1 wherein the imaging transducer is an ultrasound imagingtransducer.
 3. The catheter device of claim 2 wherein the ultrasoundimaging transducer is a selected from the group consisting of: anannular phased array a rotatable transducer.
 4. The catheter device ofclaim 3 wherein the phased array transducer is operative to image 360degrees about the first blood vessel.
 5. The catheter device of claim 1wherein the marker includes a cage on the catheter, said cage comprisesa plurality of longitudinal members disposed at circumferentially spacedapart locations about a hollow interior space, a first one of saidlongitudinal members being located at a circumferential position that isaxially aligned with the path that will be followed by the tissuepenetrator as it is advanced from the catheter.
 6. The catheter deviceof claim 1 wherein the tissue penetrator includes a needle member formedof resilient material that is biased to a preformed curvedconfiguration, said needle member being initially disposed in aretracted position within the catheter and subsequently advanceable fromthe catheter to an extended position wherein the needle member assumesits preformed curved configuration.
 7. A catheter device that is useableto facilitate penetration from the lumen of a blood vessel within apatient's body in which the catheter device is positioned to a targetlocation within the patient's body, said catheter device comprising: aflexible catheter having a proximal end and a distal end, said catheterbeing transluminally advanceable into said blood vessel; a tissuepenetrator that is advanceable from the catheter to penetrate from thelumen of a blood vessel to a target location, provided that the catheteris rotationally oriented within the blood vessel such that the tissuepenetrator is aimed at the target location; an imaging transducer thatcomprises a plurality of imaging elements fixedly mounted on thecatheter to provide an imaging signal from which an image of the targetlocation and other anatomical structures located adjacent the bloodvessel can be obtained; and said imaging elements being mounted on thecatheter at known circumferential locations relative to the path thatwill be followed by the tissue penetrator as the tissue penetratoradvances from the catheter, said imaging transducer being therebyuseable by the operator to rotationally orient the catheter such that,when the tissue penetrator is advanced from the catheter, the tissuepenetrator will extend into the target location as desired.
 8. Acatheter device as defined in claim 7 wherein the imaging transducer isan ultrasound imaging transducer.
 9. A catheter device as defined inclaim 8 wherein the ultrasound imaging transducer is a phased arraytransducer.
 10. A catheter device as defined in claim 9 wherein in thephased array transducer is operative to image 360° about the first bloodvessel.
 11. A catheter device as defined in claim 7 further comprising amarker which creates, on the image obtainable from the imaging, anindication of the path direction in which the penetrator will advancefrom the catheter.
 12. A catheter device as defined in claim 11 whereinthe marker comprises an imaging structure formed or mounted on thecatheter, said imaging structure comprising a plurality of longitudinalmembers disposed at circumferentially spaced apart locations about ahollow interior space, a first one of said longitudinal members beinglocated at a circumferential position that is aligned with the path thatwill be followed by the tissue penetrator as it is advanced from thecatheter.
 13. A catheter comprising: a catheter body having a proximalend, a distal end and a peripheral wall; said catheter of body beingreceivable within a blood vessel of a human patient; said catheter bodyhaving a penetrator lumen that terminates distally at an exit locationon the peripheral wall of the catheter; a penetrator operatively engagedto exit from the penetrator lumen, out of the exit location, and toadvance away from the catheter body on a predetermined penetrator path;and a phased array transducer fixedly mounted to the catheter body, saidphased array transducer comprising a plurality of transducer elementspositioned at circumferentially spaced apart locations, at least one ofsaid transducer elements being in a known circumferential locationrelative to said exit port to provide an imaging signal from which animage of the target location and other anatomical structures locatedadjacent the blood vessel can be obtained to enable the operator torotationally orient the catheter until the target location is alignedwith the location of the exit port such that when the tissue penetratoris advanced from the catheter it will extend into the target location asdesired.
 14. A catheter as defined as in claim 13 including an imageablemarker which includes a plurality of circumferentially spaced imageablemembers which can be sensed by the phased array transducer, said theimageable members being carried by the catheter body in a knowncircumferential orientation relative to the exit location so that theycan be used to locate the target location and in identifying the angularorientation of the exit location.
 15. A catheter as defined in claim 13wherein the phased array transducer comprises a plurality of imagingelements arranged on the catheter body with at least one of saidelements being at a known circumferential location relative to said exitlocation whereby said at least said one element is useable to identifythe angular orientation of the exit location.
 16. A catheter as definedin claim 13 wherein the catheter body is sized to be receivable in anartery of a human patient.
 17. A catheter comprising: an elongatedcatheter body having a proximal end, a distal end, a guidewire lumenopening at the distal end of the catheter body and a peripheral wall, atleast a distal region of said catheter body being flexible; saidcatheter body being receivable within a first blood vessel of a humanpatient; said catheter body having a penetrator lumen terminatingdistally at an exit location on the peripheral wall and a penetratordisposed within said lumen and advanceable out of said exit location;said catheter body including a major section which includes the proximalend and said exit location and a distal tip section extending from themajor section to the distal end of the catheter body; said distalportion of the distal tip section being of smaller cross sectional areathan the adjacent region of the major section; and an active imagingapparatus carried by the catheter body and including imaging elementsthe distal tip section and a lead extending proximally from said imagingelements.
 18. A catheter as defined in claim 17 wherein the majorsection terminates distally in a distal opening and a proximal portionof the distal tip section is received in said distal opening and adistal portion of the distal tip section extends distally of said distalopening.
 19. A catheter as defined in claim 18 including an imageablemarker on said distal portion of the distal tip section.
 20. Apercutaneous, transluminal method for creating a flow channel between afirst blood vessel that has a wall and a lumen and a second blood vesselthat has a wall and a lumen, said method comprising the steps of: A.providing a catheter device that comprises: i. a catheter having aproximal end and a distal end, said catheter being advanceable into thelumen of the first blood vessel; ii. a tissue penetrator that isadvanceable from the catheter, said tissue penetrator being operative topenetrate from the lumen of a first blood vessel, through the walls ofthe first and second blood vessels and into the lumen of a second bloodvessel when the catheter is positioned and rotationally oriented withinthe first blood vessel such that the tissue penetrator is aimed at thesecond blood vessel; iii. an imaging transducer fixedly mounted on thecatheter to provide an imaging signal from which an image of the secondblood vessel and other anatomical structures located adjacent the firstblood vessel can be obtained; and, iv. an imageable marker on thecatheter to provide, on the image obtainable from the imaging signalfrom the imaging transducer, a penetrator path indication indicative ofthe path that will be followed by the tissue penetrator when the tissuepenetrator is advanced from the catheter; B. percutaneously insertingand transluminally advancing the catheter into the first blood vessel;C. actuating the imaging transducer and moving the catheter within thefirst blood vessel until the penetrator path indication is aimed at thelumen of the second blood vessel; and, D. advancing the tissuepenetrator from the catheter, through the walls of the first and secondblood vessels and into the lumen of the second blood vessel.
 21. Themethod of claim 20 wherein the tissue penetrator is an elongate memberthat has a lumen extending longitudinally therethrough and wherein saidmethod further comprises the step of: E. advancing a first crossingguidewire through the lumen of the tissue penetrator and into the lumenof the second blood vessel.
 22. The method of claim 21 wherein themethod further comprises: F. retracting the tissue penetrator into thecatheter leaving the first crossing guidewire in place such that itextends from the lumen of the first blood vessel into the lumen of thesecond blood vessel.
 23. The method of claim 22 wherein the catheterdevice provided in Step A has a main guidewire lumen that extendslongitudinally through at least a portion of the catheter and whereinthe method further comprises the steps of: I. moving the first crossingguidewire from the lumen of the tissue penetrator, and reintroducing acrossing guidewire into the main guidewire lumen of the catheter; and,H. readvancing the catheter over the first crossing guidewire to aposition wherein the catheter extends through the lumen of the firstblood vessel, through the openings created in the walls of the first andsecond blood vessels by advancement of the tissue penetrator in Step D,and into the lumen of the second blood vessel.
 24. The method of claim23 wherein the method further comprises the steps of: I. actuating theimaging transducer and moving the catheter within the second bloodvessel as required to cause the penetrator path indication to be alignedwith the lumen of the first blood vessel; and J. advancing the tissuepenetrator from the catheter, through the walls of the first and secondblood vessels and into the lumen of the first blood vessel.
 25. Themethod of claim 24 further comprising the step of: K. advancing a secondcrossing guidewire through the lumen of the tissue penetrator and intothe lumen of the first blood vessel.
 26. The method of claim 25 whereinthe method further comprises: L. retracting the tissue penetrator intothe catheter leaving the second crossing guidewire in place such that itextends from the lumen of the first blood vessel into the lumen of thesecond blood vessel and back into the lumen of the first blood vessel.27. The method of claim 26 wherein the method further comprises thesteps of: M. providing a connector delivery catheter accompanying aradially expandable connector; N. advancing the connector deliverycatheter over the second crossing guidewire and implanting the radiallyexpandable connector such that the connector extends from the lumen ofthe first blood vessel, through the openings created in the walls of thefirst and second blood vessels in Step D, through the lumen of thesecond blood vessel, through the openings created in the walls of thefirst and second blood vessels in Step J and back into the lumen of thefirst blood vessel.
 28. The method of claim 24 wherein the method iscarried out to bypass an obstruction in the first blood vessel andwherein the openings created in the walls of the first and second bloodvessels in Step D are proximal to the obstruction and the openingscreated in the walls of the first and second blood vessels in Step J aredistal to the obstruction.
 29. A catheter device according to claim 13wherein the phased array imaging transducer comprises an annular arrayof transducer elements, at least one of said transducer elements being apenetrator path indicator element that is in known spacial relationshipto the path that will be followed by the tissue penetrator as the tissuepenetrator is advanced from the catheter.
 30. The catheter device ofclaim 29 further in combination with an image display screen fordisplaying an image received from the phased array transducer.
 31. Thecatheter device of claim 29 wherein indicia are provided on the imagedisplay screen to distinguish between the portion of the image beingreceived from the penetrator path indicator transducer element and thoseportions of the image received from the other transducer elements. 32.The catheter device of claim 31 wherein said indicia are selected fromthe group of indicia consisting of: a series of hash marks that indicatethe circumferential location of the image received from said penetratorpath indicating element; and, a line that indicates the circumferentiallocation of the image received from said penetrator path indicatingelement.
 33. The catheter device of claim 31 wherein the portion of theimage received from the penetrator path indicating transducer element iselectronically modified to be visually discernible from the remainder ofthe image received from the other transducer elements.
 34. A catheterdevice that is useable to penetrate from the lumen of a patient's bloodvessel in which the catheter device is positioned to a target locationwithin the patient's body, said catheter device comprising: a catheterthat has a proximal end and a distal end, said catheter beingadvanceable into said first blood vessel; a tissue penetrator that isadvanceable from the catheter, said tissue penetrator being operative topenetrate from the lumen of the blood vessel to target location providedthat the catheter is rotationally oriented within the first blood vesselsuch that the tissue penetrator is aimed at the target location;catheter braid being incorporated in at least a portion of said catheterbody, said catheter braid having a braid angle and a pick count, thebraid angle of said catheter braid being such that the pick count isless than 100 picks per inch to thereby minimize the longitudinalelongation of the catheter that may occur as the catheter is warmed fromroom temperature to body temperature.
 35. The catheter device of claim34 wherein the braid angle is such that the pick count is 20-30 picksper inch.